1) No reason to tough out low carb flu. Many don't even experience it because
2) Sodium. Increase it if you have no medical reason to follow a low sodium diet. 9 times out of 10 when I'm feeling sluggish for my brisk walks the problem is fixed with a boullion cube.
3) No experience with with eating more carbs for energy. I'd try the salt and if that doesn't work then try increasing carbs.

If you do them both at the same time, you'll not know which was effective.

I work out in the morning fasted. Currently that includes short strength training followed by 6 miles on the treadmill- about 4.5 running and 1.5 brisk walk so I can finish in under an hour.

I took advice Dr Phinney had in a video that was recently posted in another thread and have some salt before I head to the gym. No fatigue issues at all. If it wasn't for time restraints, I feel like I could keep running much longer.

Once fat adapted, there is no reason for carbs unless you are really pushing near your limit for an extended period of time.

I had a similar lack of endurance/energy when I started working out fasted, but after about 2 weeks it went away and I was able to do much more with what felt like much less effort...hang in there and give your body time to adapt...though, I don't see how trying a bit more salt could hurt...

KnitOrMiss wrote: »

Since you're just back on the low carb wagon, you'll have to go through adapation and rewiring of muscular mitochondria all over again. Expect bonking for 2-12 weeks. I would probably make a low carb gatorade for part way through as a test, but the problem is that your muscles are still burning glucose, so when they bonk, they bonk. It will take a while for them to remember using fat/ketones for fuel. Upping carbs will only prolong the adjustment and the misery if you aren't intending to having them ongoing.

Pretty much this. I have had similar issues lately as I've had some carb creep. In addition to the adjustment to being fat adapted, I think you are going to find that 50g-100g is a bit too high at some point to efficiently become fat adapted.

If you want to become fat adapted while engaging in high intensity exercise, the most efficient method is going to be cutting carbs even further and spreading them out throughout the day (so don't eat 30g of carbs all at once). But that is also going to be tough and you will continue to bonk at every exercise for a few weeks until you get there. This is what I would suggest, and I also suggest taking a break when you become light-headed.

If you can't keep your balance, can't concentrate, can't visually focus (i.e. fuzzy vision), then you need to take a break and sit down. Once you become fat adapted, this will stop happening. For now, your body's primary energy source is still glucose. These symptoms are occurring because your muscles are using up glucose faster than it can be replenished through glycogen release and gluconeogenesis. As a result, your brain is starving for energy because there isn't enough for both your muscles and your brain. Taking a break from exercise will allow glucose creation (from glycogen, protein - including muscle, and fat - both dietary and body) to "catch up" because glucose can finally be created faster than you are using it. Once your muscles have converted and become fat adapted, they will use fat as a primary energy source. This means muscles can directly oxidize fat at a faster rate than the average person, and will rely less on glucose. The end result is that glucose use / depletion happens more slowly during exercise than it does today; and slowly enough to allow replenishment to keep up... or almost keep up, in some cases with a small enough gap to be unnoticeable.